We have purchased a house with an established grape vine that has not been cut back. . . . . ever. It produces a lot of beautiful grapes. I don't want to kill it but it is completely out of control. The plan is to cut it back and build a trelis system to keep it organized and lift it off the ground. I don't know what I am supposed to cut. I believe it is a cab grape if that helps? I'm pretty sure the vines are over 30 years old. Please help!!!
Grapes don't mind heavy pruning; so you can remove as much growth as you want. I assume that the vine is no longer dormant; so it will bleed abundant sap if it is pruned now. I would wait until the new shoots are long enough to show new flowers. Then select some shoots that you want to keep for fruiting this year. These shoots should originate as close as possible to the main trunk of the vine and should be considered for future training onto a trellis. Then you can remove all parts of the vine past the selected shoots. The removal can be done at any time; I prune my vines all summer to eliminate any growth that doesn't support this year's or next year's crop.
